Variable temperature micropillar compression to reveal basal slip properties of Zircaloy-4

2019 ◽  
Vol 162 ◽  
pp. 451-455 ◽  
Author(s):  
Siyang Wang ◽  
Finn Giuliani ◽  
T. Ben Britton
Author(s):  
Na Li ◽  
Lingwei Yang ◽  
Chuanyun Wang ◽  
M.A. Monclús ◽  
Dongfeng Shi ◽  
...  

Author(s):  
J. Cadoz ◽  
J. Castaing ◽  
J. Philibert

Plastic deformation of alumina has been much studied; basal slip occurs and dislocation structures have been investigated by transmission electron microscopy (T.E.M.) (1). Non basal slip has been observed (2); the prismatic glide system <1010> {1210} has been obtained by compression tests between 1400°C and 1800°C (3). Dislocations with <0110> burgers vector were identified using a 100 kV microscope(4).We describe the dislocation structures after prismatic slip, using high voltage T.E.M. which gives much information.Compression tests were performed at constant strainrate (∿10-4s-1); the maximum deformation reached was 0.03. Thin sections were cut from specimens deformed at 1450°C, either parallel to the glide plane or perpendicular to the glide direction. After mechanical thinning, foils were produced by ion bombardment. Details on experimental techniques can be obtained through reference (3).


2002 ◽  
Vol 724 ◽  
Author(s):  
Elizabeth R. Wright ◽  
R. Andrew McMillan ◽  
Alan Cooper ◽  
Robert P. Apkarian ◽  
Vincent P. Conticello

AbstractTriblock copolymers have traditionally been synthesized with conventional organic components. However, triblock copolymers could be synthesized by the incorporation of two incompatible protein-based polymers. The polypeptides would differ in their hydrophobicity and confer unique physiochemical properties to the resultant materials. One protein-based polymer, based on a sequence of native elastin, that has been utilized in the synthesis of biomaterials is poly (Valine-Proline-Glycine-ValineGlycine) or poly(VPGVG) [1]. This polypeptide has been shown to have an inverse temperature transition that can be adjusted by non-conservative amino acid substitutions in the fourth position [2]. By combining polypeptide blocks with different inverse temperature transition values due to hydrophobicity differences, we expect to produce amphiphilic polypeptides capable of self-assembly into hydrogels. Our research examines the design, synthesis and characterization of elastin-mimetic block copolymers as functional biomaterials. The methods that are used for the characterization include variable temperature 1D and 2D High-Resolution-NMR, cryo-High Resolutions Scanning Electron Microscopy and Differential Scanning Calorimetry.


2020 ◽  
Author(s):  
Xinkai Qiu ◽  
Sylvia Rousseva ◽  
Gang Ye ◽  
Jan C. Hummelen ◽  
Ryan Chiechi

This paper describes the reconfiguration of molecular tunneling junctions during operation via the self-assembly of bilayers of glycol ethers. We use well-established functional groups to modulate the magnitude and direction of rectification in assembled tunneling junctions by exposing them to solutions containing different glycol ethers. Variable-temperature measurements establish that rectification occurs by a bias-dependent tunneling-hopping mechanism and that glycol ethers, beside being an unusually efficient tunneling medium, behave identically to alkanes. We fabricated memory bits from crossbar junctions prepared by injecting eutectic Ga-In into microfluidic channels. Two 8-bit registers were able to perform logical AND operations on bit strings encoded into chemical packets as microfluidic droplets that alter the composition of the crossbar junctions through self-assembly to effect memristor-like properties. This proof of concept work demonstrates the potential for fieldable molecular-electronic devices based on tunneling junctions of self-assembled monolayers and bilayers.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 533e-533
Author(s):  
Krista C. Shellie

The objective of this research was to investigate whether the medium used to transfer heat to a commodity influenced the mortality of Mexican fruit fly larvae. A similar 2-h heat dose was delivered to grapefruit via immersion in a variable temperature water bath or via exposure to a rapidly circulating gas. The concentration of oxygen and carbon dioxide inside the grapefruit was analyzed at 30-min intervals and grapefruit center temperatures recorded every 60 s during heating. The mortality of larvae located inside grapefruit during heating in a controlled atmosphere or in hot water was significantly higher than that of larvae located inside grapefruit heated in air. The internal atmosphere of grapefruit heated in a controlled atmosphere or in hot water contained significantly higher levels of carbon dioxide and lower levels of oxygen than grapefruit heated in air. Larval mortality was compared after larvae were heated in media by rapidly circulating air or by an atmosphere containing 4 kPa of oxygen and 18 kPa of carbon dioxide to evaluate whether the altered atmosphere or a heat-induced fruit metabolite was responsible for enhanced mortality. The significantly higher mortality of larvae heated in media in the presence of an altered atmosphere suggested that the altered atmosphere enhanced larval mortality. Results from this research suggest that reducing oxygen and or increasing the level of carbon dioxide during heating can enhance mortality of the Mexican fruit fly and potentially reduce the heat dose required for quarantine security.


2020 ◽  
Author(s):  
Nicolò Maria della Ventura ◽  
Szilvia Kalácska ◽  
Daniele Casari ◽  
Thomas Edward James Edwards ◽  
Johann Michler ◽  
...  

Author(s):  
Hai Bi ◽  
Chao Jing ◽  
Peter Hasch ◽  
Yuxiang Gong ◽  
Daniel Gerster ◽  
...  

2008 ◽  
Vol 1091 ◽  
Author(s):  
Hung-Keng Chen ◽  
Po-Tsun Liu ◽  
Ting-Chang Chang ◽  
S.-L. Shy

AbstractVariable temperature electrical measurement is well-established and used for determining the conduction mechanism in semiconductors. There is a Meyer¡VNeldel relationship between the activation energy and the prefactor with a Meyer¡VNeldel energy of 30.03 meV, which corresponds well with the isokinetic temperature of about 350 K. Therefore, the multiple trapping and release model is properly used to explain the thermally activated phenomenon. By the method, an exponential distribution of traps is assumed to be a better representation of trap states in band tail. Samples with higher temperature during measurement are observed to show better mobility, higher on-current and lower resistance, which agree well with the multiple trapping and release model proposed to explain the conduction mechanism in pentacene-based OTFTs.


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